Use event handlers for link state callback

Allows DHCP to listen for device disconnect and refresh ip lease on reconnect.

features/netsocket/emac-drivers/TARGET_WHD/interface/WhdSTAInterface.cpp

@@ -46,6 +46,12 @@ struct whd_scan_userdata {
 
 static whd_scan_userdata interal_scan_data;
 static whd_scan_result_t internal_scan_result;
+static uint16_t sta_link_update_entry = 0xFF;
+static const whd_event_num_t sta_link_change_events[] = {
+    WLC_E_SET_SSID, WLC_E_LINK, WLC_E_AUTH,  WLC_E_ASSOC, WLC_E_DEAUTH_IND, WLC_E_DISASSOC_IND, WLC_E_DISASSOC,
+    WLC_E_REASSOC, WLC_E_PSK_SUP, WLC_E_ACTION_FRAME_COMPLETE, WLC_E_NONE
+};
+
 
 extern "C" void whd_emac_wifi_link_state_changed(whd_interface_t ifp, whd_bool_t state_up);
 
@@ -143,6 +149,30 @@ whd_security_t whd_fromsecurity(nsapi_security_t sec)
     }
 }
 
+static void *whd_wifi_link_state_change_handler(whd_interface_t ifp,
+                                                const whd_event_header_t *event_header,
+                                                const uint8_t *event_data,
+                                                void *handler_user_data)
+{
+    UNUSED_PARAMETER(event_data);
+
+    if (event_header->bsscfgidx >= WHD_INTERFACE_MAX) {
+        WPRINT_WHD_DEBUG(("%s: event_header: Bad interface\n", __FUNCTION__));
+        return NULL;
+    }
+
+    if (event_header->event_type == WLC_E_DEAUTH_IND ||
+            event_header->event_type == WLC_E_DISASSOC_IND) {
+        whd_emac_wifi_link_state_changed(ifp, WHD_FALSE);
+    }
+
+    if (whd_wifi_is_ready_to_transceive(ifp) == WHD_SUCCESS) {
+        whd_emac_wifi_link_state_changed(ifp, WHD_TRUE);
+    }
+
+    return handler_user_data;
+}
+
 MBED_WEAK WhdSTAInterface::OlmInterface &WhdSTAInterface::OlmInterface::get_default_instance()
 {
     static OlmInterface olm;
@@ -204,12 +234,19 @@ nsapi_error_t WhdSTAInterface::connect()
 
 #define MAX_RETRY_COUNT    ( 5 )
     int i;
+    whd_result_t res;
 
     // initialize wiced, this is noop if already init
     if (!_whd_emac.powered_up) {
         _whd_emac.power_up();
     }
 
+    res = whd_management_set_event_handler(_whd_emac.ifp, sta_link_change_events,
+                                           whd_wifi_link_state_change_handler, NULL, &sta_link_update_entry);
+    if (res != WHD_SUCCESS) {
+        return whd_toerror(res);
+    }
+
     if (!_interface) {
         nsapi_error_t err = _stack.add_ethernet_interface(_emac, true, &_interface);
         if (err != NSAPI_ERROR_OK) {
@@ -239,7 +276,6 @@ nsapi_error_t WhdSTAInterface::connect()
     whd_security_t security = whd_fromsecurity(_security);
 
     // join the network
-    whd_result_t res;
     for (i = 0; i < MAX_RETRY_COUNT; i++) {
         res = (whd_result_t)whd_wifi_join(_whd_emac.ifp,
                                           &ssid,
@@ -290,6 +326,12 @@ nsapi_error_t WhdSTAInterface::disconnect()
     if (res != WHD_SUCCESS) {
         return whd_toerror(res);
     }
+    whd_emac_wifi_link_state_changed(_whd_emac.ifp, WHD_FALSE);
+
+    res = whd_wifi_deregister_event_handler(_whd_emac.ifp, sta_link_update_entry);
+    if (res != WHD_SUCCESS) {
+        return whd_toerror(res);
+    }
 
     // de-init Offload Manager
     if (_olm != NULL) {

features/netsocket/emac-drivers/TARGET_WHD/interface/whd_emac.cpp

@@ -115,7 +115,6 @@ bool WHD_EMAC::power_up()
         if (CY_RSLT_SUCCESS == res) {
             drvp = cybsp_get_wifi_driver();
             powered_up = true;
-            ifp->whd_link_update_callback = whd_emac_wifi_link_state_changed;
             if (link_state && emac_link_state_cb) {
                 emac_link_state_cb(link_state);
             }
@@ -291,5 +290,3 @@ extern "C"
     }
 
 } // extern "C"
-
-